This invention relates to a digital decoder for a transmitting-and-receiving-multi-antenna digital wireless transmission chain. This digital decoder is intended to determine symbols transmitted in linear space-time coded transmission signals, based on a convolutional binary coding.
The invention is particularly useful for application in the field of transmission or radio broadcasting of digital data, in particular in the case of transmission with mobiles or, in a more general manner, in the case of wireless or hard-wired networks. In a more precise manner, the invention applies advantageously in the context of the IEEE standards 802.11a and IEEE 802.11g when, on transmission, the signal has been subjected to a linear space-time coding based on binary coding. As a reminder, the standard specifies only a binary coding.
In a general manner, systems combining a multiplicity of antennas for transmission and reception, or MIMO (Multiple Input, Multiple Output) systems make it possible to increase the capacity and reliability of transmission chains, in particular by using space-time coding. This space-time coding makes it possible to transmit successive symbols via the plurality of transmission antennas on sending. On reception, there are numerous detectors implementing reception algorithms such as, in particular, linear receivers based on the setting to zero criterion or minimising the mean squared error. This invention relates rather to algorithms based on maximum likelihood, which authorize best performance in terms of error rate. However, standard receivers based on such an algorithm present major complexity from the point of view of design.